1. Technical Field
The present disclosure relates to a substrate and a manufacturing method thereof, and more particularly to a semiconductor substrate and a manufacturing method thereof.
2. Description of the Related Art
In a conventional semiconductor substrate, the outermost circuit layer is embedded in a surface of an insulation layer of the substrate, and exposed from the surface of the insulation layer. As an exposed surface of the circuit layer may be coplanar with the surface of the insulation layer, during bonding to a flip chip, if warpage occurs on the circuit substrate, part of bumps (for example, solder balls) of the flip chip may not contact the circuit layer, causing an open circuit, resulting in product failure.
A solution is forming bumps (for example, copper pillars) on the exposed surface of the circuit layer, and then bonding to the flip chip. However, bumps formed in the existing manners have a problem of offset, that is, the bumps cannot be located right on the pads of the circuit layer, but may cover part of the surface of the insulation layer. Such situation is unallowable when the distance between circuits is closer and denser, because it easily results in that the bumps of the flip chip simultaneously contact the offset bump and adjacent pad or trace thereof, to cause a bridge, resulting in produce failure.